JPS59193080A - Light emitting semiconductor device - Google Patents

Abstract

PURPOSE:To enable to regulate the position of installing a semiconductor laser element on the stem with a high accuracy by a method wherein the titled device is constructed in such a manner that a light emitting semiconductor element is arranged on the main surface side of the stem and a thermal cooling device is fixed to the back side of the stem. CONSTITUTION:A heat block 5 is fixed on the pedestal part 16 of the stem 2 via solder 19. Besides, the semiconductor laser element 7 is fixed to the block 5 via sub mount 5a. On the other hand, the thermoelectric cooling device 4 is fixed in the recess of the back surface of the stem 2 via resin material 20. Further, a cap 13 having a transparent window 12 is hermetically fixed to the main surface of the stem 2 and packages each elememt. Since the interposal of the device of a dimensional accuracy such as the thermo-electric cooling device is not allowed in such a structure, the height of the element 7 to the stem 2 becomes constant. Therefore, the write accuracy stabilizes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a light emitting semiconductor device, and particularly to a semiconductor laser device.

[Setsuki technology]

As is well known, in recent years semiconductor laser devices have been used as light sources for digital audio disc pickups, optical video disc players, and optical memories.
・Started to use it as a light source for discs (1981)
Nikkei Electronics, September 14th: 138-152
Page [Semiconductor laser that meets the demands of audio discs-1).

However, in front of the semiconductor laser device, it cannot be said that sufficient output is being obtained for a small light source. In particular, large output is required for @ writing to printers and disks. For this reason, semiconductor laser devices are often used near their output limits, making it difficult to stabilize their characteristics.

Therefore, the present applicant has developed an entire semiconductor laser device having the structure whose main parts are shown in FIG. That is, this device has 8
A thermoelectric cooling device 4 from a Peltier element is fixed to the main surface of a stem 2 through which a glue board 1 is insulatively fixed through a resin material 3 to form an FC structure, and the heat generating surface of the thermoelectric cooling device 4 is formed. is fixed to the stem. Further, a heat block 5 having a protrusion in the center is similarly fixed on the heat absorption surface, which is the upper surface of the thermoelectric cooling device 4, via a resin material 6.

Further, a semiconductor laser element 7 is fixed to the vertical wall of the protrusion of the heat processor 25 via a submount 5ai. This semiconductor laser element 7 emits laser light 8 from its upper and lower ends, and the upper laser light is not used for writing. In addition, there is a heat pro with 8 laser beams directed downward.
The light intensity is detected by the h* light receiving element 9 fixed on the inclined surface of the mirror 5. In addition, a temperature detection element (thermistor) 10 is inserted into the heat pro 5 and measures the temperature of the semiconductor laser element 7. It is designed to be detected. Also, the government supply of each element and the inner end of each lead 1 are not shown, but are they wires? connected via. Further, a transparent plate 11 is attached to the main surface of the stem 2, and a cap 13 having an fc transparent window 12 is hermetically fixed to cover the metal elements, leads, etc. Note that this device is used by being attached to the heat sink 14.

This type of device indirectly detects the temperature of the semiconductor laser element 7 by detecting the temperature of the heat processor 5, performs cooling control using the thermoelectric cooler 4, and increases the output of the semiconductor laser element 7. ing.

However, it is clear from the inventor of this invention that such a technique causes new problems as described below.

(1) The thermal lightning cooling device 4il-i has poor dimensional accuracy between the heat absorption surface and the heat generation surface. Insert between the stem 2 and the heat exchanger 5 through the resin material 3.6. Due to this gap, the height of the laser oscillating part from the main surface or back surface of the stem 2, which is the base wall surface, changes depending on the mounting. Each heat cooling device is made of compound semiconductors made of metals such as Bi, Tθ, and SB. For this reason, heat frost removal 1 device 4? When you move it, it generates heat and stretches. Due to the green color of the dough, the distance between the disc surface and the laser emitting part changes when writing on the disc surface, and the diameter of the spot during writing changes, resulting in a 1-7 drop in the writing accuracy.

(21. The 13 caps are fixed to the stem 2 with a hermetic seal, but at this time, the stem shears are also heated.
Gas is generated from the resin tube 36 that connects the thermoelectric cooling device 4, the stem 2, and the heat block 5, and there is a risk that the cows will be fed up and the reliability of the laser installation will be reduced.

(3) The semiconductor laser cable 7 is assembled in direct contact with the thermoelectric cooling device 4 having a large thermal resistance, in which a plurality of compound semiconductor elements are all arranged between Jλ ceramic plates. Therefore, after completing the assembly, I decided to perform a lifespan test on the semiconductor laser device (a test in which the laser device is driven to maintain a constant optical output in a sub-temperature environment and the change in operating current is examined over time; hereinafter referred to as screening). However, the influence of the thermal resistance of the thermal lightning cooling device is large, making it difficult to obtain accurate evaluation data for semiconductor laser devices.Therefore, there is a drawback that it is not possible to inspect the characteristics of the device after it is assembled.

[Purpose of the invention]

An object of the present invention is to provide a light emitting semiconductor device in which the position of a semiconductor laser element on a stem does not easily change during operation.

Another object of the present invention is to provide a light emitting semiconductor device in which the pick-up position of a semiconductor laser element on a stem can be determined with high precision.

Another object of the present invention is to provide a highly reliable light emitting semiconductor device in which deterioration of the characteristics of a semiconductor laser element is difficult to occur.

Furthermore, another object of the present invention is to
An object of the present invention is to provide a light-emitting semiconductor device that is capable of screening semiconductor laser devices.

The above and other objects and novel features of the present invention include:
It will become clear from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief summary of representative inventions disclosed in this application is as follows.

That is, in the present invention, a semiconductor laser element, a light receiving element that receives the laser light emitted from the semiconductor laser element, and a resistor that detects the temperature of the semiconductor laser element are provided on the main surface side packaged by the cap of the stem. By creating a structure in which the thermoelectric cooling device, which has rough dimensional accuracy and expands during creation, is fixed with resin material on the back side of the main surface of the stem, the light emitting height of the semiconductor laser element can be assembled with high precision. During use, the height of the light emitting part is not changed due to displacement of the thermoelectric cooling device, and during assembly and heating, the thermoelectric cooling element is fully fixed through the resin material outside the paragassing of the stem. This prevents the gas from being trapped inside the package, preventing deterioration of the semiconductor laser element. Furthermore, since the heat generated in the half-quartet laser element during screening is quickly transferred from the stem to the heat sink, it is now possible to detect the quality of the conductor laser element.

[Example 1] Fig. 2 is a sectional view showing the main parts of a light emitting semiconductor device (semiconductor laser device) according to an embodiment of the present invention, Fig. 3 is a bottom view of the same, and Fig. 4 is an optical output of the semiconductor laser device. 2 is a graph showing the temperature dependence of .

This semiconductor laser device is fixed to a disc-shaped stem A2 made of a thermally conductive metal such as Cu through a glass insulator 15 as shown in FIG. are doing. The stem 2 is pre-squeezed by pressing so that the central part protrudes, and 17 depressions are formed on the main surface side of the stem 2 and on the entire back surface side of the pedestal section 16. In particular, the stem 2 has a wire tension space 18 on the entire back side of the stem, with the part where the two leads 1 are attached shallowly. This wire tension space 18 communicates with the recess 17.

On the other hand, on the pedestal part 16 of the stem 2, there is a heat pro 1. The material 5 is fixed through a preparation (for example, Pb-8u low melting point solder).

1. A heat processor is mounted in the trench, and a semiconductor laser element 7 is mounted on the vertical wall of the protruding part of the groove 5 in a position that emits laser light 8 from the upper and lower ends. (Fixed through.'!l: Female, Heat Pro 2. A light receiving element 9 is fixed to the cylindrical surface of the ri 5, and it receives the laser beam 8 directed downward and detects the entire laser beam intensity. Since the light-receiving element 9 is mounted on an oblique surface, the laser light reflected from the light-receiving element surface does not proceed to the outside of the coloring through the transparent window, which will be described later. The far field pattern of the laser beam 8 emitted from the transparent window is not disturbed.In addition, the heat block 5 is not provided with an inserter, and this insertion hole is provided with a temperature detecting element 10.
1- A mister is inserted and the temperature of the semiconductor laser element 7 is detected through the heat pro and the hook 5. For reasons of convenience, it is desirable that the insertion hole be provided as close to the semiconductor laser element 7Vc as possible.

ilc, the semiconductor laser device 7. Light receiving element 9. Each of the two electrodes of the thermistor 10 is connected by a wire (not specifically shown) to the upper end of the IJ-domain 1 outside the two reeds passing through the wire tension space 18.

On the other hand, a thermoelectric cooling device 4 is fixed to the recess 17 on the back surface of the stem 2 via a resin material 20.

For the joint 20, resin or low melting point solder is used. The thermoelectric cooling device 4 has an endothermic surface sloped to the back surface of the stem 2,
The heat generating surface faces the heat sink 14 which will be the board during mounting (
′! & tactile surface. Furthermore, the wires 21 extending from the two poles of the thermal lightning cooling device 4 extend through the wire tension space 18 and are connected to the two wires 1, respectively.

Furthermore, a transparent plate 11 such as glass is provided on the main surface of the stem 2.
(i- Attach the transparent window I2' (+- type H-shape 1ζ cab 9. The tab 13 is airtightly fixed by a ring weld, and all the elements, etc., are packaged.

Such a semiconductor laser device has a semiconductor laser element 7.
All of the laser light 8 is used as a light source for writing on a memory disk, for example. At this time, the laser beam 8 is monitored by the light receiving element 9, and the semiconductor laser element 7 is controlled so that the light intensity is constant. On the other hand, the thermoelectric cooling device 4 operates to cool the heat block 5 and to maintain the temperature of the semiconductor laser element 7 at a constant temperature. Control of the thermoelectric cooling device 4 is achieved by temperature detection information from a thermistor 10. As for the light intensity (light output Po) of the laser beam 8, as shown in the graph of FIG. 4, the lower the temperature, the greater the light output. Therefore, the semiconductor laser element +7 is kept at 25° C. by the thermoelectric cooling device 4, and a high-output laser beam is emitted to completely cool the memory disk.

〔effect〕

(1) Is the thermoelectric cooling device fixed to the back of the stem, and the semiconductor laser element sub-mounted to the heat block fixed on the main surface of the stem? Since the structure is such that a component with low dimensional accuracy such as a thermal lightning cooling device is completely interposed, the height attached to the stem of the semiconductor laser element is constant. Therefore, the spot diameter of the laser beam on the disk surface is always constant, and writing accuracy is stabilized.

(2) As described in (1) above and 1c, a thermal lightning cooling device that expands during operation is not present between the stem and the semiconductor laser element. For this reason, even if the thermal lightning cooling device operates and is displaced by several μm in the optical axis direction of the laser beam, it is outside the stem and the bonding material between the stem and the thermal lightning cooling device acts as a buffer. , the height of the light emitting part relative to the stem does not change. Therefore, in combination with the effect of (1) above, the spot diameter of the laser beam becomes constant, and the accuracy of the disk erosion is stabilized.

(3) Even if gas is emitted from the resin material that fixes the thermoelectric cooler due to the heat generated during the hermetically sealing of the cap, this gas will not come into contact with the semiconductor element because it is outside the package. . Shimetae S improves the reliability of semiconductor laser devices.

(4) Does this semiconductor laser device include multiple compound hand conductor elements between one ceramic plate? Screening can be performed before installing a thermal lightning cooling device with large fC thermal resistance. i*, 2% Even with the cooling device installed, the heat transfer path is sub-mounted.

It becomes a heat block and a stem, and the thermal resistance is smaller than that of the structure shown in FIG. As a result, screening becomes possible.

(5) Since the thermal lightning cooling device is located outside the stem, it is convenient because it can be easily replaced if the thermal lightning cooling device breaks down.

[Embodiment 2] FIG. 5 is a sectional view of a main part of a light emitting semiconductor device (semiconductor laser device) according to another embodiment of the present invention.

This device is a semiconductor laser device in which a thermal lightning cooling device is not attached to the back surface of the stem 2 from the beginning, and the stem 2 has a pedestal portion 16 on the main surface as in the previous embodiment. It has a recess 17 on the back surface, and a semiconductor laser element 7 is placed on the pedestal part 16.
．． Light receiving element 9. The heat block 5 to which the thyristor 10 is attached is fixed. The upper end of the twisted part 1 is fixed to the stem 1 and connected to each element 7 through a wire (not shown).
It is connected to the electrode of 9.10° and the N sharp bend. The package is removed with a cap 13 having a transparent window 12. A part of the stem 2 is provided with a wire drawing space 22 that communicates with the hollow 17, and serves as a drawing space for two wires of a thermal lightning cooling device disposed in the hollow 17. It should be noted that the other parts are the same as those in the previous embodiment, so a complete explanation will be omitted. Also, the name 1 will be used as is.

In such a device, first, the thermal lightning cooling device 4 is placed or fixed on the heat sink 14 so that the heat generating surface is in contact with the heat sink 14. Thereafter, the semiconductor laser device is stacked on top of this so that the thermoelectric and cooling device 4 enters the recess 17. At this time, an adhesive such as silicone grease or resin material having excellent thermal conductivity is interposed between the stem 2 and the thermal lightning cooling device 4. Further, the wire 21 serving as the terminal of the thermal lightning cooling device 4 is taken out from the wire drawing space 22 and connected to a predetermined part.

〔effect〕

This embodiment achieves the same effects as the first embodiment.

[Embodiment 3] FIG. 6 is a cross-sectional view of the main parts of a light-emitting semiconductor device (semiconductor device for optical communication #) according to another embodiment, and FIG. 7 is a schematic diagram showing an example incorporated into an optical communication system. be.

The semiconductor device for optical damage has the structure of Embodiment 11 shown in FIG. 2, except for the structure of the cap 13. For the sake of brevity, explanations of other parts having the same structure will be omitted.

The cap 13 has a stepped hole 23 with a large diameter in the upper part at the center thereof, and a tubular ceramic in the large diameter part.

Jisleep 24'! ]l-Inserted. An optical fiber 25 is inserted into this ceramic sleeve 24, and the inner end is connected to the light emitting part (resonator end) of the semiconductor laser element 70.
They are wearing each other. In addition, a solder material 2 is provided in the small diameter portion of the stepped hole 23.
6 is embedded, and the optical fiber 25 is hermetically fixed to the cap 13. Further, the outer end of the optical fiber 25 is flush with the outer end of the ceramic sleeve 24 protruding from the carriage 13.

Such an optical communication semiconductor device 27 is incorporated into an optical communication system as shown in FIG. That is, the device 27
is arranged on the substrate 29 of the optical communication device 28. Board 29
includes a laser drive circuit 30 for driving and controlling the semiconductor laser element. A Bertier control circuit 31 is incorporated which controls the entire thermoelectric cooling device 4 to always operate the semiconductor laser element at a desired temperature. Further, temperature monitor information 32 by the thyristor is transmitted to the Beltier control circuit 31, and light intensity monitor information 33 is transmitted to the laser drive circuit 30, respectively.

Such an optical communication device 28 receives an analog signal 35 as a digital signal 36 via a modulator 34, and sends the optical signal to a receiver 37 using the optical fiber 25 as a transmission medium. In the receiver 37, an optical converter 38 such as a silicon photodiode converts the optical signal into an all-electric signal, and the optical signal is amplified by an amplifier circuit 39. Thereafter, a demodulator 40 converts the digital signal 36 into an analog signal and removes all communication information.

〔effect〕

This implementation 1) has the same effect as punishment example 12.
,Soshi1. Therefore, when applied to optical communication systems, the distance between the inner end of the optical fiber and the laser emitting part is always constant,
The laser emission position does not change even during laser beam oscillation.

This woman, the laser beam socket contacts the optical fiber without changing its diameter, and the light absorption efficiency in the optical fiber is high and stable. As a result, stable optical communication can be performed.

Although the invention was recently carried out by the inventor of the present invention and was explained in detail based on Being able to change it is not an easy thing to do.

[Usage division] The above explanation mainly describes the entire background of the invention made by the present inventor and the case where it is applied to video discs and optical communication technology, which are the field of application, but is not limited to that. It is also applicable, for example, to laser beam printer technology, or at least to light emitting technology in the intermediate field.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the main parts of a semiconductor laser device developed by the applicant, FIG. 2 is a sectional view showing the main parts of a semiconductor laser device according to an embodiment of the present invention, and FIG. 3 is a bottom view. , FIG. 4 is a graph showing the temperature dependence of the optical output of a semiconductor laser device, FIG. 5 is a cross-sectional view of a main part of a semiconductor laser tube according to another embodiment of the present invention, and FIG. 6 is a still another embodiment. FIG. 7 is a schematic diagram showing an example of incorporating the semiconductor laser device into an optical communication system. 1... Lead, 2... Stem, 3, Resin interest, 4...
・・Thermoelectric cooling device, 5・-Heat Pro 1. 5 a1
R mount, 6... Resin material, 7. Semiconductor element, 8... Racer light, 9 Light reception; +''a, ]0.
・Temperature detection element (thermistor), 11・rfb light 4f
z, 12... Transparent window, 13... Cap, 14 Coat sink, 15... Insulator, 1 (i... Pedestal anatomy..., 17-
・Concave, 18... Wire tension space, 19 Plate, 20
Registry/(4, 21...Wire, 22...Wire drawing fil L-empty nL 23...Stepped hole, 24. Ceramic, Knulieve, 25 Optical fiber, 26 Preparation, 2
7. Optical communication device for communication, 28. Optical communication device, 29. Motomura, 30. Racer drive circuit, 31...
Peltier side 1 circuit, 32...Temperature monitor information, 33
Light intensity monitor information, 34... Modulator, 35... Analog signal, 36... Digital signal, 37 - Injured person,
3B... Optical converter, 39... Amplifier circuit, 40...
φ adjuster. Agent Patent Attorney Akio F. Figure 1 Figure 2 Figure 3 Figure 21/7 Figure 4-' Sumitomo-IF (94 Figure 5 Figure 6 Figure 7 Figure S City

Claims (1)

[Scope of Claims] 1. A stem, and a light emitting semiconductor element (fl) disposed on the main surface side covered by the sockaging member, and a female thermal lightning cooling device fixed to the back side of the stem; A light emitting semiconductor device having: 2. The light emitting semiconductor device according to claim 1, wherein the light emitting semiconductor element is a semiconductor laser element.